Sound record and method of producing the same



v. H. EMERSON. SOUND RECORD AND METHOD 0F PRODUCING THE SAME. APPLICATION FILED APR. 20.1920.

15,41 @342% Patented May T69 11922,

NETE@ STATES PATENT @FFTCEQ VICTOR H. EMERSON, 0F NEW YORK, N. Y., ASSIGNOR TO EMERSON PHONOGRAPH COMPANY, IN C., 0F NEW YORK, N. Y., .A CORPORATION Oll NEW YORK.

Laissez.

Specification of Letters Patent. A

raient-ea May is, rasa.

Application filed April 20, 1920. Serial No. 375,243.

To all Lo/wmV 'it may concern.'

Be it known that I, VICTOR H. EMERSON, a citizen of the United States, residing at the city, county, and State of New York, have invented new and useful Improvements in Sound Records and Methods of Producing the Same, of which the following is a speciication.

My invention relates to phonographrecords and methods for their production, and has for an object economically to produce a device of the class described having increased durability and efficiency.

Another object of my invention more particularly described is to form a composite phonograph record having superior reproducing qualities due to the peculiarly adaptable properties of certain of the elements employed in practising my invention.

Numerous attempts have been made to fabricate a commercial record of different materials with a view to cheapening its manufacture and otherwise attempting to improve upon this type of record, and to'thi's 25 end such records have, for example, been made up in layers, i. e., .with a layer of record material, so called, reinforced by a body portion of different composition, such as paper or materials possessing similar properties.

Thus a variety of laminated records have heretofore been brought out with varying success as to practical and wearing results, many of them possessing serious defects due to the fact, among other considerations, that in the present state of the art the commercial record in the nal stage of its` manufacture must receive its grooved record face by action of a matrix stamper impressed with great force into the surface of the blank of which the record is formed. Hence, it is highly important to have the entire substance or body portion of the blank of material that will not only withstand the high pressure incident to the stamping operation referred to, but will rigidly present the record surface to the stampers and support the same in such firm manner that all the minute irregularities or sound undulations of the material shall be imprinted to their full depth and with the greatest attainable accuracy; and furthermore it is important not only that the irregularities representative of sound waves be accurately recorded, but that the record thus made shall be permanently retained by the medium into which those ir, regularities are indented precisely to the full depth and width of the sound waves which they represent, if maximum efficiency be attained.

The pressure resisting and form sustaining features of a record blank having been record thereby produced will have the geni eral characteristics described` but I have introduced other features which as far as I am aware have not heretofore been employed in the production of a commercial phonograph record. namely, features comprising among others the employment of a layer or layers possessing the properties and characteristics of certain metals and having record material upon the outer or top surface, and upon the opposite face of the metal disk a second disk is added similar in form but of a relatively yielding material sufficient to permit the rigid non-yielding metal portion to conform to the general surface contour of the matrix, notwithstanding that such metal sheet although thus cushioned retains sufiicient stiffness and rigidity to receive all of the matrix undulations, however minute and delicate they may be.

In its broad aspects my invention therefore comprises as an indispensable element the unyielding layer possessing the characteristics of the harder metals employed in the manner described and as a contributing feature to facilitate the process of the manufacture of my improved record, under specified conditions there is applied to the metallic body the additional or under layer of relatively yielding non-record material above `referred to. Hence, the metal thus coacting with its under or cushioning layer disk, not only sustains the thin veneer of record material in form and position most effectual for receiving the pressing operation of the stamper or matrix, but also because of its terial may be applied upon one face of the metal plate, and the non-record or cushion material on the others in any convenient way, in conformity to the general scope of my invention, but preferably in the employment thereof I previously treat the respective surfaces of the metal plate, the one face for receiving the record material, the other for receiving the pad or paper layer, with an acid or other corrosive agent that will slight ly roughen these surfaces so as to cause a more firm and permanent union of the specified materials with the metal, as described. The depth of the irregularities thus formed in the -metallic surfaces will obviously depend upon the length of time the expansion to the contact continues-and one familiar with the requirements to make a record usable and commercial will readily determine the period necessary properly to prepare the surface of the metallic layer for the reception of record material or the subsidiary layer.

It is apparent that in pressing a record bla-nk with a metallic disk employed as a component in the manner described, if the metal plate be of uniform gage of thickness and if its under side, during the pressing of a matrix thereon, rests upon a perfectly flat surface base, then, in order t-o obtain prac` tical results the surface of the matrix should be disposed in accurate correspondence therewith. Thus, should the engaging surface plane of the matrix plate not conform in exact parallelism with that of the face of the disk to be stamped thereby. the face of the matrix would be mashed into flat conformity to the plane or level of the base plate upon which the record blank is resting at the moment. Hence, even though such variation between the respective surfaces of the stamper and blank be extremely slight. irreparable damage mightl be caused to the face of the matrix owing to the unyielding property of the metal, were some provision not made to compensate for any such unconformity.

To overcome this diliiculty I place a layer of cardboard or other relatively tirm mate'- rial which will yield only to an extent sufliciently to conform to the contour or general level of the face of the matrix, or of the two matrices when a double disk is pressed. as will presently be more fully described.

The foregoing description relates to the formation of a record having sound undulations upon a single face. lVhen a double faced record is made in accordance with my improved method I employ two metal plates separated by the relative yielding layer above describedas an under or cushioning disk. The metal disks will each have one surface prepared with a coat-ing of record material in the manner above described, and the reverse faces of the disks thus brought together form a single blank, but are separated by the relatively yielding or compressible layer. 1 The separating layer will'thus act as a pad or cushion to absorb or compensate for any under pressure caused by unevenness of either or both of the matrix plates when pressure of the matrix press has been applied in the process of stamping the record.

Having reference to the drawings illustrative of a preferred form of the embodiment of the record of my invention and apparatus employed in theprocess ofits manufacture,-

Figure 1 represents the top surface of a metal disk showing a pitted surface partly covered with record material laid thereon.

Fig. 2 is an enlarged edge view of the disk shown in Fig. l.

Fig. 3 is the representation of a type of press for impressing matrices upon the oppolsite faces of a record, with record materials,

shown greatly exaggerated, in a preparatory position for pressing.

Fig. 4 is a view. also enlarged, of the record components shown in Fig. 3 immediately after pressing has been applied forming a record.

Fig. 5 is an enlarged partial view of the record as shown in Fig. 4 having had its rough edges removed. i

Referring to the illustrations: The' numeral l represent-s a disk of thin metal which because of the relative inexpensiveness of sheet steel, may preferably be of that metal, having roughened surfaces upon its respective faces upon a portion of the topi surface of which is shown a fragmentary layer of record material 3 having sound grooves i impressed therein and the usual central orifice 5 shown therethrough.

The record 'material 3 comprising the usual earthy material` shellac and the other ingredients familiar to those engaged in the making of sound records, may be laid over the surface of the metal sheet in any convenient way, in the form of so-called record dust to an even depth, as shown in Figs. 1 and 2. and fixed thereto by means of any adherent agent by japanning or by applying suflicient heat directly to the material, or as a mass to be flattened out `by the pressure of the matrix stamper. In almost any form applied"` the metal plates will retain the recording layer more eifectually if the adjacent surface has first been pitted, even though only slightly lroughened, for the record material will thus seek out and enter the infinitely small and numerous cavities thereby forming a-much more neatly integrall I therefore employ in the preferred form of vmy improved processy as preliminary steps thereof the preparation of a disk plate 0f thin metal, preferably formed of sheet steel of substantially the diameter of the record to-be made therefrom, having 'a centering orifice 5. The disk is then immersed in a bath of a suitable corrosive mixture for .a predetermined exposure to the action thereof, after which all traces of the acid are removed from the disk surface. I next apply upon one face of the metal disk a layer of record material uniformly to the desired depth, preferably in a finely powdered form, and slightly heat the plate with its dusted layer until it becomes sufficiently plastic to adhere to the surface.

I next prepare a disk 6 of thick paper or cardboard of slightly greater diameter tha-n the metal disk 1, as shown best in Fig. 4, and having the same central orifice 5, to which paper disk I apply a coating 7 of shellac or varnish, or any convenient thermoplastic agent, as shown in exaggerated form in Fig. 3, and place the sheet metal disk concentrically thereon,` as shown in Fig. 1.

Thus combined, my record in its simplest form, i. e., for making a single faced record, is ready .to be submitted to the stamping process or pressing step of my improved process;` but as already pointed out, I contemplate forming sound'records having phonographic records upon both of their faces, and, therefore, I add the coating of thermo; plastic adhesive vmaterial 7 to the surfaces of the paper disk 6 and in the manner described apply the metal disks 1, both of which have'been prepared in the manner described, and with the three disks thus arranged With their orifices 5 1n axial or concentric alignment, they are centered upon the pin 12 of the matrix 10 of the press 9 which has a matrix 11 secured tothe upper plate 8 of the press.

In connection with the simple form of press 9 illustrated in the' drawings, means are shown for introducing a heating medium for softening the record material and the other thermo-plastic constituents employed in building up the record blank. Thus the vtion of the record, and which rough or bed plate 8 has the respective intake and discharge pipes 12 and 12a while the upper plate 8a has like connections 13 and 13EL which may bev employed for conducting steam or other medium for introducing heat into the upper and lower plates of the press for the purpose above explained. However, any suitable type of press may be used so long as the required degree of heat may' be imparted to the thermo-plastic materials immediately preceding the application of pressure in formingthe rec-ord, t-he particular form thereof being no part of my invention. Vhen the layers have been thus subjected to the required heat and pressure a surplus of the respective plastic materials will exude around the edge and form a rim 14 upon the peripheries of the disks Wholly or partially concealing the laminated construcrounded edge as a final operation of 'my process is ground off after having become suiicientlyhardened for the purpose.

Having described my invention, What I claim is: f

1. A method for forming sound records which comprises the following steps; preparing a thin metal disk, roughening the surfaces of the disk and applying record material directly to one surface and a disk of cardboard'to the other surface thereof.

2. A method for forming sound' records upon a metallic disk which consists in -applying a layer of'record material directly to one surface and. adisk of cardboard to theother of said surfaces. g

3. A method for forming' sound records upon a metal disk by means of corroding the surfaces thereof, applying a layer of thermo-plastic record material directly to 105 one, surface and attaching a disk of relatively yielding material to the other surface thereof.

1. A method for forming sound records upon a metal disk by means of corroding the surfaces of the metal ,and applying a layer of thermo-plastic record material directly to one surface and attaching a disk of relatively yielding material to the other surface thereof b-y means of a thermo-plastic 115 material.

.-5. A method for forming sound records which consists in preparing a. disk of'thi'n metal, corroding the surfaces thereof and adding a. layer of record material directly to one of the surfaces,coating the other surface of the said disk with a thermo-plastic Y g roughening the surfaces thereof' and dusting a layer of powdered thermoplastic record material directly 1119011 one of said surfaces, applyingsuticient heat" tov cause said record material to adhereto said surface, then app lyi'ng a layero-f relatively `yielding material to-ftheother surfaceof the metal disk 'by'ineans ofythermo-plastic material, and. submitting th'edi'sksv thus'l prepared to heat' and pressing/upon the surface having recordj material thereO-Il'am'atr'ixof 'a sound record.

7 method for..forming` sound records which 'consists in` preparing disks of metalV and'c'ardboard having; similar central o-rices and uniting them by means ,ofl a suitable adhesivermedium' app-lying record mate- 8.1A'ine'tl'1'd for'y `sound reco-rds which consistsin preparing disks of metal and cardboard having similar central orifices and vuniting themy by means of suitable ad- 4'hesive medium and.l applying record material directly tothe 'exposed surface of the metal disk by heat and pressureand indenting a sound groove therein. y

Y9.-A-'m'ethod` forI forming sound records which consists inprepa'ring two similar disks ofrnietal and a."siini lardisfk of cardboard, attaching the lI'netal ydisksy to the respective faces 'ofthe cardboard, applying record ma- Lterial directly to-thefouter faces o-fthe metal disks and'pressing sound lmatrices thereon.

10. A method fr forming sound records consistingl in preparing two similar disks of metal, roughening their surfaces by corrosion, prepa-ring a'disk of 'cardboard of suitable' thickness and applying thermo-plastic material to the faces of the paper, placing 4 rial for causing said. layers to adhere toi .gether, and a layer of thermo-plastic record material directly upon said metal disk having a sound reco-rd 'impressed thereon.

sound record comprising a metal tothefexposed. surface of the disk with a coating of record material therey rectly upon said metal disk having a groove v thereon containing undulatio-ns representative oil-sound waves.

14. A sound record comprising a. layer of thermo-plastic record material upon a metal disk superimposed upon a 'similar disk of paper of suitable thickness secured thereto by thermo-plastic material directly and a sound record impressed in said record material.

15. A sound record having layers of metal and a layer of record material intimately united to the metal. l

16. A sound record. having a layer of metal and a layer of thermo-plastic record materialintimately united to a surface of the metal.

17.v A sound record having a-disk of metal with a pitted surface and a layer of record material pressed into said surface and a.l

sound groove pressed into said material.

18. A sound record having a disk of met-al with a pitted surface, a layer of record ma-l terial upon said pitted surface and a cushion disk attached to said metal disk.

19. A sound record disk having metal disks with pitted surfaces, record material in their layers intimately attached to a surface of said metal disks and a cushioning layer between said metal disks.

20. A sound record comprising a disk of rial permanently attached thereto anda cushion layer attached to said disk.

21. A sound reco-rd comprising a disk of` relative-ly hard material having roughened surfaces, said disk imposed upon a layer of yielding material and having a layer of record' material withirregularities representative of sound waves thereon.

' ln testimony whereof l have hereunto set my hand.

vioror H. EMERSON.

lrelatively hard material with record mate- 

